Deflections may occur in fuel tanks due to pressure and vacuum changes, e.g., due to differences between atmospheric pressure around the tank body and the pressure of a gaseous mixture of air and fuel vapor in the fuel tank body. For example, when gas pressure in the tank body exceeds atmospheric pressure, the top of the tank body may expand away from the bottom of the tank body. When atmospheric pressure exceeds the gas pressure in the tank body, the top of the tank body may collapse toward the bottom of the tank body.
Pressure and vacuum changes experienced by a fuel tank may increase when sealed evaporation control (EVAP) systems are employed to reduce evaporative emissions and fuel leakage, e.g., in hybrid electric vehicles. For example, fuel tanks may be partially reinforced by increasing thickness of fuel tank walls and/or including structural elements within the fuel tank body in addition to various non supportive components such as sensors and fuel delivery components within the fuel tank body.
In one particular approach, a non-supportive fuel delivery module (an integrated system that combines various fuel system components in a single unit positioned in the fuel tank body) may be included in a fuel tank body. Such fuel delivery modules may not provide structural reinforcement to fuel tanks For example, a non-supportive fuel delivery module may include a top flange and bottom cup which are slidably connected, e.g. through sliding steel rods and coil springs, such as described in U.S. Pat. No. 7,159,578.
The inventors herein have recognized issues with such approaches. For example, structural elements included inside a fuel tank may reduce fuel storage volume and available space for sensors and/or fuel delivery components, e.g., a fuel delivery module. Additionally, increasing fuel tank wall thickness may lead to higher material costs and greater fuel tank weight, which may lead to lower fuel efficiency in a vehicle, for example.
To at least partially address these issues, a system is provided comprising: a fuel tank including an upper wall and a lower wall; and a support member, where the support member includes a plurality of fuel system components and the support member is coupled to the upper and lower walls of the fuel tank. In some examples, the support member may be a structurally supportive fuel delivery module.
In this way a fuel tank may be reinforced without the addition of structural elements in the body of the fuel tank which impinge on fuel storage volume and/or lead to higher material costs. Further, fuel tank deformation may be reduced when subjected to pressure and vacuum changes. Additionally, fuel tank wall thickness may be reduced leading to lower material cost and increased fuel efficiency.
It should be understood that the background and summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.